The present invention pertains generally to medical equipment and, more particularly, to a dual mode catheter system and method for using same appropriate for use in percutaneous coronary intervention. The present invention pertains more specifically still to a dual mode catheter combining the abilities of an over-the-wire catheter with the abilities of a MONORAIL (trademark) catheter for use in percutaneous coronary intervention whereby a dual-lumen catheter can be used for delivery of drugs, contrast fluids, and other desired elements through a lumen adapted to further be used for over-the-wire use while simultaneously having a second lumen adapted for use by a shorter wire.
Percutaneous transluminal coronary angioplasty (PTCA) is a procedure which is well established for the treatment of blockages in the coronary arteries. For example, blockages may occur from cholesterol precipitation on the coronary wall which may be in any stage from initial deposit through aged lesions. PTCA is a technique performed through the skin (percutaneous) inside an artery (transluminal) of the heart (coronary), for example to reshape (angioplasty) that artery. Percutaneous transluminal angioplasty (PTA) is also a known treatment of other types of blocked body lumens.
In general, catheters are used to advance a medical device, such as a balloon or stent, or medical fluid, such as a drug or a contrast fluid, into an artery of a patient to accomplish a desired task inside the artery. For example, in many of today""s surgical procedures, medical devices such as catheter mounted angioplasty balloons, incisors, stents and artherectomy cutters are routinely introduced into patients"" cardiovascular systems in accordance with prescribed protocols.
One commonly used apparatus for introducing these medical devices is a guide wire. Typically, whenever a guide wire is used for the purpose of introducing a medical device into the cardiovascular system of a patient, the guide wire is pre-positioned in situ, usually through an introducer catheter which is used to establish an access site into the patient""s cardiovascular system. In a typical operation, the guide wire is positioned within an artery or other vessel. As the catheter is advanced over the guide wire, a proximal end of the guide wire will remain outside or emerge from a side wall aperture such that the proximal portion of the guide wire remains outside of the catheter as the catheter is advanced to its desired operative site. If it becomes necessary or desirable to exchange a device such as with a balloon dilation catheter, the proximally exposed portion of the guide wire can be secured and stabilized manually by an operator while the first catheter is removed and a second catheter is slid over guide wire.
The most widely used form of percutaneous angioplasty makes use of a dilatation balloon catheter. In typical PTCA or PTA procedures, the cardiovascular system of a patient is accessed with an introducer, usually via the femoral artery, brachial artery, or radial artery. All other devices including a guiding catheter are percutaneously introduced into the cardiovascular system of a patient through the introducer and advanced through a vessel until the distal end thereof is at a desired location in the vasculature. A guide wire and a medical device are introduced through the guiding catheter with the guide wire sliding through the dilatation catheter. The guide wire is first advanced out of the guiding catheter into the patient""s coronary vasculature and the requisite device such as a dilatation catheter is advanced over the previously advanced guide wire until the device is properly positioned and the desired procedure is then performed.
At present, two general types of catheters are utilized in clinical practice such as in percutaneous coronary intervention: so-called xe2x80x9cover-the-wirexe2x80x9d catheters using full length guide wires and xe2x80x9cmonorailxe2x80x9d catheters using shorter guide wires than the over-the-wire catheters. MONORAIL is a trademark of SciMed Life Systems, Inc., One SciMed Place, Maple Grove, Minn., United States of America 55311. Each of these catheter systems has advantages as well as disadvantages. The dual mode catheter of the present invention combines an over-the-wire catheter with a monorail catheter to allow simultaneous use of and switching between the MONORAIL (trademark) and over-the-wire catheters in situ, for example to manipulate stents, balloons, other medical devices, or combinations thereof.
A wide variety of catheters have been developed in the prior art. For example, U.S. Pat. No. 5,776,111 issued to Tesio teaches a multiple catheter assembly having two single catheters each having multiple lumen. Tesio ""111 also discusses other typical examples of a multiple lumen catheters such as a dual lumen catheter, commonly known as Tesio catheters, in which one lumen in the catheter tube introduces fluids and the other lumen in the tube removes fluids. Tesio ""111 does not teach or suggest having over-the-wire and MONORAIL (trademark) capabilities simultaneously present in a single catheter. In the prior art, such a delivery tube is incapable of supporting a guide wire.
The present invention allows greater control of the medical devices and the catheter by a single physician while simultaneously allowing distal injection of individual components such as iodinated contrast fluids or drugs. Other advantages will be apparent to those of ordinary skill in the medical arts such as reducing necessary exposure to radiation for both doctor and patient.
Over-the-wire catheters incorporate a guide wire lumen extending substantially through the entire length of the catheter. The guide wire lumen is typically separate from catheter mounted devices such as balloons, stents, and the like.
After positioning the guide wire, the catheter mounted medical device is then subsequently advanced through a guiding catheter and over the guide wire. During the advancement of the catheter over the wire, however, it is extremely important for the physician to maintain positive control over both the stability of the guide wire and the advancement of the catheter. Further, it is important that the means for controlling the stability of the guide wire and the means for controlling the advancement of the catheter be relatively close to each other and relatively near the introductory access site into the patient.
An over-the-wire catheter may be used with numerous devices such as stents, balloons, and the like, and also allows distal injections of iodinated contrast fluids and drugs. Further, over-the-wire catheter may be advanced, the guide wire exchanged, and/or a wire tip reshaped without losing ground in situ such as within a coronary artery. However, the long guide wire used in over-the-wire catheters can be difficult to steer when attempting to accurately position the stents, balloons, and the like. Further, advancing such medical devices around, through, or across a coronary obstruction is not easily performable by a single operator.
One solution to the control problem for an over-the-wire catheter is to provide a guide wire of sufficient length so that any extracorporeal portion of the guide wire is longer than the catheter that is being introduced over the wire. Typically, over-the-wire systems incorporate a three hundred centimeter length guide wire. This, however, can be cumbersome and may require manipulation of the system at a substantial distance from introductory access site. A solution to this problem has been the use of so-called MONORAIL (trademark) catheters.
In a MONORAIL (trademark) style of angioplasty catheter, a guide wire lumen extends through only a distal portion of the catheter, typically from a distal tip orifice to a proximal aperture formed in the side wall of the catheter body. The MONORAIL (trademark) catheters in use today have a relatively short guide wire deployed near the distal tip of the catheter so that the guide wire can be separated from the catheter. Typically, MONORAIL (trademark) wires are around one-hundred eighty centimeters in length. This arrangement, however, still requires the physician to effectively control both the guide wire and the catheter.
For over-the-wire systems, exchanging a catheter of device, sometimes desired, is difficult and requires greater exposure to fluoroscopy and radiation. Moreover, such exchanges are not readily performable by a single operator.
MONORAIL (trademark) catheters do not provide for distal injection of iodinated contrast fluids or drugs or the like. Wire exchanges and wire tip reshaping are not performable without removing the wire entirely from the body, leading to loss of ground of any initial advancement within the coronary artery. Second lumen within MONORAIL (trademark) catheters may allow for passage of wires such as those to deliver radioactive therapies, but do not extend through the entire length of the catheter and are not adapted to receive and support a guide wire.
Several catheters and techniques for positioning medical devices in the cardiovascular systems of patients have been previously proposed in the prior art. For example, U.S. Pat. No. 5,951,568 to Schatz teaches an over-the-wire catheter including a catheter that is formed with a lumen for receiving a guide wire there through. In operation, the guide wire is pre-positioned as desired and an end of the guide wire is then passed through an orifice of a connector and is inserted into the guide wire lumen of the catheter. The distal end of the catheter is then inserted over the wire and through the orifice of the connector. The catheter is advanced through the orifice of the connector and over the guide wire. No suggestion is made to combine a short wire style catheter with an over-the-wire style.
U.S. Pat. No. 5,976,106 to Verin et al teaches a dual or triple lumen catheter wherein the lumen means may be closed distally. The catheter may comprise a long guide wire lumen with an entry and an exit distal of the balloon, which advantageously results in a two lumen catheter construction. The catheter may also comprise a guide wire lumen with an entry distal of the balloon and an exit proximal of the balloon. However, Verin ""106 teaches that the long guide wire lumen is closed at one end and that the purpose of such a long guide wire lumen is not for use as an over-the-wire catheter guide or fluid delivery but rather as a means to allow entry of a radioactive emitter, which makes limiting travel within the long guide wire lumen necessary for safety purposes. No teaching or suggestion exists to combine over-the-wire and MONORAIL (trademark) for simultaneous use. Verin ""106 also teaches a balloon at the distal functional end.
U.S. Pat. No. 5,817,053 to Agarwal teaches a guide catheter exchange device for exchanging a guide catheter advanced over a balloon catheter and a coronary guide wire without removing the coronary guide wire in percutaneous transluminal coronary angioplasty. In one embodiment, the exchange device comprises two sections and a connecting device for connecting the sections. In a separate embodiment, the invention pertains to a guide catheter exchange device for exchanging a guide catheter employed by a MONORAIL (trademark) balloon catheter.
As noted in Agrawal ""053, a report in Catherization and Cardiovascular Diagnosis 33, pp. 284-287 (1994) describes a catheter reported to contain two inner lumen and four ports providing a partial MONORAIL (trademark) design wherein the exchange technique requires a moderate amount of operator skill and a learning curve. The exchange of the guide catheter requires threading the coronary guide wire through an exit port of the exchange device located 120 cm proximal to the distal tip of the device and reinserting the coronary guide wire through a re-entry port of the exchange device located 130 cm proximal to the distal tip of the device.
U.S. Pat. No. 5,571,089 issued to Crocker teaches a low profile perfusion catheter for use in coronary angioplasty applications. In one embodiment, an axially movable tubular support is movable within a lumen from a proximal, insertion position to a distal perfusion position. In a further embodiment, a porous drug delivery balloon is provided. Crocker ""089 teaches away from a dual mode catheter.
Accordingly, the prior art, although discussing possible use of either over-the-wire or MONORAIL (trademark) catheters, discusses these as mutually exclusive alternatives. No suggestion is made to combine an over-the-wire catheter with a MONORAIL (trademark) catheter. No suggestion is made to provide a second guide wire lumen capable of supporting a manipulatable guide wire there through in addition to allowing use such as for fluid or drug delivery.
Moreover, disadvantages still remain. None of the prior art catheters teach simultaneous provision of or switching between a MONORAIL (trademark) and an over-the-wire catheter in situ, for example to manipulate stents, balloons, other devices, or combinations thereof. No prior art exists that teaches how to allow distal injection of individual components such as iodinated contrast fluids or drugs while simultaneously allowing a MONORAIL (trademark) catheter to be in place.
Accordingly, an improved dual mode catheter is described.